I recently encountered this error.
The error disappeared after I installed ImageMagick-imagick and php5, without having to add other plugin.
Perhaps the information will be very helpful to someone else
I did all the things here from this post, and I ended up undoing them all, nothing worked, so I read your comment.
Yes that helped me, thank you very much, I will leave details here to help someone, because I came across this error and worked on it in the past 5 hours.
I have php 7.0-fpm, before I had php5-fpm that my server auto updated via virtuamin, without me knowing, so I ran out of magick.
sudo apt-get install php-imagick //this installs imagick for php 7.0, install for your version do not know if it is the same, try
então editei o arquivo:
/etc/php/7.0/fpm/php.ini
and I added this line, I put comment with my name on everything I do on the server, to find all the changes I made, change 1 change 2 etc ...:
;MYNAME1
extension=imagick.so
;MYNAME1
então reiniciei os serviços:
service php7.0-fpm restart
service apache2 restart
I hope my comment helps someone as well.
Did you help me with your comment! Thank you.